1. Technical Field
The present invention relates generally to photonic devices. More particularly, certain embodiments relate generally, but not exclusively, to an apparatus and method for performing dispersive spectrometry.
2. Background Art
As the portable device market grows, the need for compact and energy efficient sensors has increased. Recent improvements in optical spectroscopic sensors have provided for increasingly diverse applications in biological and environmental sensing. Spectrometers are an essential component for optical spectroscopy. A photonic integrated circuit (PIC) includes monolithically integrated photonic devices or elements and can be useful as a spectrometer in applications such as biological and environmental sensing.
Currently, commercially available on-chip spectrometers variously rely on some array of stationary waveguides which are to propagate each to a respective detector a different wavelength of diffracted light. One limitation of this approach is that spectroscopy is typically interested in characterizing some approximation of a continuous wavelength range of a light spectrum. To better achieve this characterization, conventional on-chip spectrometry techniques seek to position output waveguides as close to one another as possible. However, such close proximity is limited by resulting crosstalk, wherein light at a given wavelength incorrectly contributes to measurements made by different detectors coupled to respective adjacent output waveguides. Where conventional techniques seek to reduce crosstalk by increasing the spacing between waveguides, continuous spectrum measurements suffer as a result.